Question

Which of the following statements is not always true?

a + (-b ) = -b + a

(a + b) + (-c) = a + [b + (-c)]

-(-a) = a

a - (-b) = (-b) -a

Answer 1

Explanation:

The answer is a - (-b) = (-b) - a

for example if we take;

a = 4

b = 2

c = 2

and we replace;

4 - ( -2) = (-2) - 4

6 = -6

which is not true....

All the remaining are true....

even u can just use the values of abc and check if its true....